When I’m writing a feature, I do all the interviews, then I spend some time thinking about the structure before I sit down to write (a lot of this thinking occurs in the shower). What one idea can bring this all together? How can I start and finish it? By the time I sit down to write, it doesn’t always go to plan but at least it always gets me started.
Even in an exam, one minute of thinking before you start writing will pay off in two minutes’ saved time during your essay, though you’ll have to forgo the shower.